I'm 30, and have a computer science degree, and am log(n) on the chart in many areas (but certainly not all). In almost all cases, the relevant experience came from me trying to do a side project that required knowledge I didn't have. I can install a database because I had to. I can program in functional languages because I was reading about them and I tried to use one for a side project.
The side projects don't even have to lead anywhere, but they get you to the point where you can say "ya, I can write a node.js server" and then you can do it on the job, and a few years later you're an expert.
This is definitely not the only way to acquire skills. I'm sure some people dig through books, or just focus on doing their job and still grow. But for me, side projects have always been the driving force.
I was a lifer Sysadmin until I was 40 and learned Ruby on Rails. I've always had an unprovable theory that Sysadmin always results in a fork in the career path: management or programming, and I didn't see myself in management. I'm self-taught and was accepted for Startup School this year, and while I'm not quite where I want to be, I think programming and creating with an awareness of the system side of things is a better direction for me to go in.
You can also always program on the side if you want to maintain the stability of an established career.
I'm ~40 and going back for a CS degree isn't very appealing / practical. But if I knew what things to study... I could start on my own.
I'm advanced in my career, but its been mostly advanced level support and system administration work. I want to get into programming.
I say all that to make the point that a degree track isn't the best fit for me.